When describing left ventricular (LV) function by echocardiography, the main focus has been to study the longitudinal and radial motion. However, a third motion that recently has gained interest is the circumferential (rotational) motion of the LV.
Different modalities have been used to describe this motion and studies have indicated LV twist to be an additional integral component in LV function (Buchalter et al. 1994; Moon et al. 1994; Dong et al. 1999; Tibayan et al. 2004). Other studies have provided detailed information on the twisting motion of the LV, by measuring regional and segmental as well as endocardial and epicardial rotation (Gustafsson et al. 2009; Goffinet et al. 2009). So far, only amplitudes of rotation have been reported, whereas the rotation pattern of the LV has not been fully described.
Earlier studies have shown systolic clockwise rotation at the base and counterclockwise rotation at the apex of the LV, creating a twist (Stuber et al. 1999; Notomi et al. 2005; Takeuchi et al. 2006). Therefore, between the opposite directions of rotation at the base and the apex, there must be a transition level with no rotation. In a previous study, a rotation of zero degrees could be measured in only one or two segments simultaneously at one level of the LV in the short-axis image in healthy subjects (Gustafsson et al. 2009). This indicates that the image plane was not parallel to the transition plane, which also means that the axis of rotation at the transition level was not congruent to the longitudinal axis, presuming the short-axis images were perpendicular to the LV longitudinal axis.
The object of the present application is to achieve a system that presents a novel way to quantify and visualize the ventricular rotation pattern of the heart.
The present invention is aimed to be used in the routine clinical practice at cardiology departments to improve the diagnostics of different cardiac diseases, through easy interpretable quantification and visualization of the rotation pattern of the left and right ventricles.